Multi-lumen-catheter retractor system for a minimally-invasive, operative gastrointestinal treatment

ABSTRACT

A system for performing minimally invasive procedures in a body lumen of a patient including a flexible catheter having a first lumen configured and dimensioned to receive an endoscope therethrough and a second lumen configured and dimensioned to receive a first flexible tube therethrough. The first flexible tube is movable through the second lumen and has a distal portion including a first curve extending in a first direction with respect to the longitudinal axis and a second curve extending in a second different direction with respect to the longitudinal axis. A retractor system is positioned at a distal portion of the catheter and is movable from a non-expanded insertion position to an expanded position forming an expanded cage to form a larger working space. The distal portion of the first flexible tube is movable within the expanded cage.

This application is a continuation in part of application Ser. No.13/726,147, filed Dec. 23, 2012, which is a continuation of applicationSer. No. 12/970,604, filed Dec. 16, 2010, now U.S. Pat. No. 8,506,479which claims priority from provisional application 61/287,077, filedDec. 16, 2009 and is a continuation in part of application Ser. No.13/913,466, filed Jun. 9, 2013, which is a continuation in part ofapplication Ser. No. 12/970,604, filed Dec. 16, 2010, now U.S. Pat. No.8,506,479, which claims priority from provisional application61/287,077, filed Dec. 16, 2009, and is a continuation in part ofapplication Ser. No. 13/531,477, filed Jun. 22, 2012. The entirecontents of each of these applications are incorporated herein byreference.

BACKGROUND

1. Field of the Invention

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disorders in aminimally-invasive manner.

2. Description of the Related Art

Endoscopic procedures involving the gastrointestinal system offeradvantages over conventional surgery in that they are less invasive andmay provide visualization. These procedures continue to evolve toaddress problems and provide new methods of treatment identified bythose skilled in the art.

One current problem includes a lack of technology for an optimalminimally-invasive expansion of a working space adjacent to the targettissues that could otherwise collapse around the target lesion or defectduring an operative treatment. Having the ability to effectively expandthe working space could markedly facilitate an intra-luminal operation.An expanded working space allows the instruments and endoscope to beindependently manipulated and properly visualized around the targettissue. One of skill would appreciate having the ability to see andapproach both the target tissue and the surrounding anatomy forreference, orientation, and surgical maneuvering.

Another current problem includes a lack of an endoscopic technology fororganizing the endoscope, instruments, and working space in a mannerthat can maximize the working space for the treatment. The largerworking space can improve the ability to manipulate the instruments (andendoscope) in a minimally-invasive manner from outside the body. Namely,it would be desirable to have a working space that has a point of entryfor the instruments that is as far as practical from the target tissueto provide additional flexibility in approaching and visualizing thetarget tissue, perhaps providing more operating room for selecting atrajectory of the instruments toward the target tissue that is, forexample, at least substantially perpendicular to the plane of dissectionof the target tissue. Having a technology to overcome this problem wouldprovide the person of skill with a system and procedure that is moredesirable for a removal of tissue.

In view of at least the above, one of skill in the art of endoscopic,gastrointestinal surgical treatments would appreciate the technologytaught herein which provides (i) a minimally-invasive expansion of theintra-luminal working space; and (ii) an organization of the endoscopeinstruments, such as the retractor and tools to maximize the workingspace and maneuverability, allowing for a maximum flexibility inapproaching and visualizing the target tissue. It should be appreciatedthat having such improvements would reduce the technical complexity, andincrease the efficacy and safety of, otherwise complex endoscopicoperations. Moreover, doing so at a low cost, while using an affordablesystem that is introduced in the subject atraumatically and in a mannerthat does not substantially disrupt the conventional colonoscopyworkflow, would be seen by those of skill as a very substantialadvancement in the field of endoscopic surgical procedures.

SUMMARY

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disorders in aminimally-invasive manner. The systems, for example, can include anendoscopic surgical suite.

In one aspect of the present disclosure, a system for performingminimally invasive procedures in a body lumen of a patient, such as agastrointestinal tract, is provided comprising a flexible catheterhaving a first lumen configured and dimensioned to receive an endoscopetherethrough and a second lumen configured and dimensioned to receive afirst flexible tube therethrough. The first flexible tube is movablethrough the second lumen and has a first channel (lumen) extendingtherethrough dimensioned and configured to receive a first endoscopictool (instrument) for axial movement therein, the first flexible tubeterminates in a distal opening and has a longitudinal axis and a distalportion movable to an angled (or curved) position with respect to thelongitudinal axis. The distal portion includes a first curve extendingin a first direction with respect to the longitudinal axis and a secondcurve extending in a different direction with respect to thelongitudinal axis. A retractor system is positioned at a distal portionof the catheter, the retractor system including first and secondflexible elements movable from a non-expanded insertion position to anexpanded position forming an expanded cage to form a larger workingspace, the distal portion of the first flexible tube movable within theexpanded cage wherein the first curve increases a distance to a targetlesion from the distal opening of the first flexible tube. A coveringcan be provided for at least a portion of the retractor system, thecovering having an opening to receive body tissue.

In some embodiments, the catheter has a third lumen configured anddimensioned to receive a second flexible tube, the second flexible tubehaving a second channel (lumen) extending therethrough configured anddimensioned to receive a second endoscopic tool (instrument) for axialmovement therein. The second flexible tube can have a longitudinal axisand a distal portion movable to an angled (or curved) position withrespect to the longitudinal axis. The distal portion includes a firstcurve extending in a first direction with respect to the longitudinalaxis and a second curve extending in a different direction with respectto the longitudinal axis. The second flexible tube can be slidableaxially within the third lumen and the distal portion of the secondflexible tube can be movable within the expanded cage.

In some embodiments, the first flexible tube and/or second flexible tubeare unattached to the catheter. In some embodiments, the distal tips ofthe flexible tubes can be substantially aligned with the longitudinalaxis when positioned within the lumens of the catheter and return to theangled position when exposed from the second and third lumens.

In some embodiments, the cage further comprises third and fourthelements, wherein upon expansion of the retractor system to the expandedposition the first, second, third and fourth elements move from theircollapsed insertion position outwardly away from a longitudinal axis ofthe catheter to the expanded position.

The system in some embodiments can include a stabilizer movable from afirst position to a second position to increase the stability andrigidity of the cage (retractor system). In some embodiments, the cageincludes a fifth flexible element, and the stabilizer comprises astabilizing element movable within a lumen of, or alternatively, over,the fifth element.

The system can include an actuator positioned at a proximal region ofthe catheter and operably coupled to the first and second flexibleelements to move the first and second elements between the non-expandedand expanded positions.

In some embodiments, a retaining (locking) mechanism is provided tomaintain the actuator in one of several positions to retain (lock) thefirst and second elements in a desired expanded position. A releasemechanism can be provided for releasing the retaining mechanism.

The system in some embodiments includes a proximal coupler to retain aproximal portion of the first and second elements and a distal couplerto retain a distal portion of the first and second elements, wherein theproximal and distal couplers can include an opening dimensioned toreceive the endoscope therethrough when the catheter is backloaded overthe endoscope. In some embodiments, a distal portion of the covering isattached to the distal coupler and a proximal portion of the covering isattached to the proximal coupler.

The covering can be closable to encapsulate tissue therein for removal.A flexible closing member such as a suture can be attached to thecovering, wherein the flexible closing member is pulled to close thecovering.

In some embodiments, a first and/or second transverse bridge member canbe provided. The first transverse bridge member can be provided to jointhe first and second flexible elements to increase the rigidity of theretractor system. The second transverse bridge member can be provided tojoin the third and fourth elements to increase the rigidity of theretractor system.

In accordance with another aspect of the present disclosure, a methodfor performing a minimally invasive procedure in a body lumen of apatient, such as a gastrointestinal tract, is provided. The methodpreferably comprises the steps of placing a flexible catheter over aproximal region of a flexible endoscope, inserting the flexibleendoscope in the body lumen to visualize target tissue, advancing thecatheter over the endoscope, expanding a retractor system from anon-expanded insertion position to an expanded position to expand thebody lumen to create a larger working space, and maneuvering a firstflexible tube within the catheter, the first flexible tube having adouble curved tip and being axially movable and rotatable within thecatheter to locate and orient the curved tip. The distal portion of theflexible tube includes a first curve extending in a first direction withrespect to the longitudinal axis and a second curve extending in adifferent direction with respect to the longitudinal axis. The methodpreferably further comprises the step of maneuvering a first endoscopicinstrument (tool) within the first flexible tube, wherein the firstflexible tube can be located at a selected position to define a fixedsecond curve and the endoscopic tool can be movable axially to adjust adistance between a distal tip of the first endoscopic tool and targettissue without changing the selected position or curvature of the fixedsecond curve.

In some embodiments, the method can include the steps of a) maneuveringa second flexible tube within the catheter, the second flexible tubehaving a double curved tip (first and second curves extending indifferent directions) and being axially movable and rotatable within thecatheter to locate and orient its distal curved tip; and b) maneuveringa second endoscopic tool within the second flexible tube, wherein thesecond flexible tube can be located at a selected position to define afixed second curve and the second endoscopic tool can be movable axiallyto adjust a distance between a distal tip of the second endoscopic tooland the target tissue without changing the selected position orcurvature of the fixed second curve.

In some embodiments, the distal tip of the first flexible tube and/orthe distal tip of the second flexible tube is normally curved and is ina substantially straightened position when in the confines of thecatheter during insertion and automatically assumes a curved positionwhen exposed from the confines of the catheter.

In some embodiments, the first and second flexible tubes areindependently axially movable and independently rotatable. In someembodiments, the flexible tubes are removably insertable through thecatheter and remain unattached to the catheter.

In some embodiments, the first and second endoscopic tools are angledtoward the target tissue to achieve triangulation with the targettissue.

The method can further include the step of inserting a workinginstrument through a working channel of the endoscope and into theworking space created by the retractor system.

The retractor system can include a covering, and the method can furtherinclude the step of closing the covering to encapsulate target tissuefor removal.

The method can further comprise the step of rigidifying the retractor.In some embodiments, a control is actuated to distally advancerigidifying structure with respect to the retractor system to rigidifyand stabilize the retractor system.

The teachings in another aspect include a floating, multi-lumen-catheterretractor system for ease of positioning in a subject. In someembodiments, the systems comprise a highly flexible outer tubeconfigured for guiding a floating channel and a floating endoscope in anat least substantially floating arrangement within the system. Thisflexible outer tube can have a lumen, a proximal end, and a distal endwith a double curve. And, during a use of the system, the floatingchannel can serve as a guide through which a tool is manipulated in atreatment of a target tissue in a subject. In some embodiments, the toolcan include a grasper, a forceps, a snare, a clamp, a scissor, a knife,a dissector, an endoscopic stapler, a tissue loop, a clip applier, asuture-delivering instrument, or an energy-based tissue coagulator orcutter. And, in some embodiments, the floating channel can have anelevator component for moving a bendable section to manipulate the tool.

In the system utilizing a floating channel, the floating channel can beat least substantially attached to the lumen of the outer tube at afirst proximal location and a first distal location, and be at leastsubstantially floating in the lumen of the outer tube between the firstproximal location and the first distal location. Likewise, during theuse of such system, in some embodiments, the floating endoscope can beat least slidably-attached to the lumen of the outer tube at a secondproximal location and a second distal location, and be at leastsubstantially floating in the lumen of the outer tube between the secondproximal location and second distal location. The floating arrangementcan increase the flexibility of the system and facilitate positioningthe system in the subject for the treatment of the target tissue.

The systems provided herein can be used in several different methods oftreatment. For example, the systems can be used in a method of treatinga gastrointestinal lesion using a multidirectional and multi-angularapproach to the lesion. The method can include positioning the system ina subject's gastrointestinal tract, the positioning including placingthe retractor in proximity to a target lesion for a treatment; expandingthe retractor to create the treatment space for use of the tool;improving visualization, for example, some lesions can be seen muchbetter when tissue is retracted and stabilized; optimally positioningthe target tissue in relation to the tool, for example, by optimizingthe position of the duodenal papilla, facilitating its cannulationduring a procedure; treating the target tissue with the tool; collapsingthe retractor; and, withdrawing the system from the subject. The lesioncan include, for example, a perforation, a tissue pathology a polyp, atumor, a bleed, a diverticuli, an ulcer, a cancerous tissue, an abnormalvessel, or an appendix.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a first embodiment of a system foroperatively treating gastrointestinal disorders in a minimally-invasivemanner, the retractor system shown in the collapsed position.

FIG. 2 is a longitudinal cross-sectional view of the system of FIG. 1.

FIG. 3 is a perspective view similar to FIG. 1 illustrating theretractor system in the expanded position.

FIG. 3A is an alternate embodiment of the retractor system shown in theexpanded position;

FIG. 4 is a side view of the retractor system of FIG. 3.

FIG. 5 illustrates the system of FIG. 1 being used to remove a lesion ina colon, the colon shown in a cutaway view to show the system inperspective, wherein the retractor system is in the expanded position,the tool channels extend from the catheter and the endoscopic toolsextend from the tool channels.

FIG. 6 is a side view of the system of FIG. 5.

FIG. 7 is a front view of the system of FIG. 5.

FIG. 8 illustrates the system inserted within the colon.

FIG. 9 illustrates a system of a copending commonly assigned priorapplication, the system shown to remove a lesion in a colon and havingan asymmetric chamber, the colon shown in a cutaway view to show thesystem in perspective, wherein the retractor system is in the expandedposition, the tool channels extend from the catheter and the endoscopictools extend from the tool channels.

FIGS. 10A and 10B are side and front views, respectively, in partialcross section of the system of FIG. 9.

FIG. 11 is a perspective view of an alternate embodiment of the systemshowing the catheter and two tool channels.

FIG. 12 is a perspective view of the catheter of FIG. 11 being insertedover the proximal end of the endoscope of FIG. 13 (prior to insertion ofthe endoscope into the colon), the retractor system shown in thecollapsed position.

FIG. 13 illustrates insertion of the endoscope through the colon.

FIG. 14 is a perspective view showing the catheter of FIG. 11 beingfurther advanced over the endoscope of FIG. 13, the retractor systemshown in the collapsed position.

FIG. 15 is a perspective view showing the catheter fully advanced overthe endoscope to the desired position adjacent the target tissue, theretractor system shown in the collapsed position.

FIG. 16 is a perspective view of the proximal end of the catheter ofFIG. 11.

FIGS. 17A and 17B are side views in partial cross-section showingmovement of the actuator from a proximal position to a distal positionto advance the rigidifying structure to stiffen the retractor system.

FIG. 17C is a perspective view similar to FIG. 15 showing an alternateembodiment of the rigidifying structure.

FIG. 17D is a perspective view similar to FIG. 17C showing therigidifying structure of FIG. 17C advanced over the flexible element.

FIG. 18 is a perspective view showing the two tool channels (guides)adjacent the proximal end of the catheter of FIG. 11 for insertiontherethrough.

FIG. 18A is a perspective view similar to FIG. 18 showing an alternateembodiment of the tool channels.

FIG. 19A is a perspective view illustrating the tool channels insertedinto the catheter of FIG. 11 and FIG. 19B is a perspective view similarto FIG. 19A illustrating an alternative embodiment of the tool channels.

FIGS. 20A and 20B are side cross-sectional views showing movement of theactuator from a proximal position to a distal position to move theretractor system from the collapsed to the expanded position.

FIG. 21A is a view similar to FIG. 15 showing the retractor system inthe expanded position and further illustrating the tool channels beingadvanced into the working space (chamber) created by the expansion ofthe retractor system.

FIG. 21B is a view similar to FIG. 21A illustrating an alternateembodiment wherein the tool channels are advanced from the catheterprior to expansion of the retractor system.

FIG. 22 is a view similar to FIG. 21A showing a first endoscopicinstrument (tool) advanced from a first tool channel.

FIG. 23 is a view similar to FIG. 22 showing a second endoscopicinstrument (tool) advanced from a second tool channel.

FIG. 24 is a view similar to FIG. 23 showing both endoscopic instrumentsfurther advanced from the tool channels.

FIG. 25 is a view similar to FIG. 24 showing the endoscopic instrumentsfurther advanced from the tool channels to dissect the lesion on thecolon wall.

FIG. 26 is a view similar to FIG. 25 showing the lesion which has beenremoved from the colon wall by the dissecting instrument placed withinthe retractor system and FIG. 26A is a view similar to FIG. 26 showingan alternate embodiment without a rigidifying structure.

FIG. 27 is a perspective view of the proximal end of the cathetershowing proximal movement of the actuator to return the retractor systemto the collapsed position for removal from the colon.

FIG. 28 is a view similar to FIG. 26 showing the retractor system in thecollapsed position with the lesion therein.

FIG. 29 is a view similar to FIG. 28 showing the covering member closedto encapsulate the lesion for removal.

FIG. 30 is a front view of the system in the expanded position of theretractor system and showing two channels extending from the catheter.

FIGS. 31A and 31B are cross-sectional views illustrating the switch forretaining the suture for closing the covering (bag).

DETAILED DESCRIPTION

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disordersendoscopically (in a minimally-invasive manner). The systems include anendoscopic surgical suite that is created by the systems disclosedherein. The surgical suite has a reversibly-expandable retractor thatexpands substantially symmetrically, and the tool channels have a doublecurved configuration described in detail below which maximize thedistance from the tool to the target tissue to thereby maximize spacefor one or more tools and/or an endoscope to each be maneuveredindependently to visualize a target tissue and treat the target tissuefrom outside the patient in a minimally invasive manner. Embodimentstaught herein can provide, among other improvements, an increase indistance between tool ports and the target tissue to enhance theindependent maneuverability and triangulation of each of the tools withrespect to the target tissue. This increase in distance can also providea way of obtaining a larger field of view. The systems taught herein,for example, can (i) enable a working space to be configured around thetarget tissue in tortuous body lumens and orifices such as thegastrointestinal tract using controls from outside the body; (ii)provide a flexible, passageway for multiple surgical tools andinstruments, such as endoscope and graspers, to be passed from outsidethe body towards the target tissues; and (iii) organize and control theinstruments such as the grasper in the working space from outside thebody.

In some embodiments disclosed herein, the catheter is placed over anarticulating endoscope by inserting the articulating endoscope through achannel of the catheter; in other embodiments the catheter is placedover a flexible endoscope by backloading the catheter over a flexibleendoscope, such as a conventional colonoscope. Then the endoscope, e.g.,colonoscope, is inserted to a position adjacent the target tissue andthen the catheter is advanced further over the flexible endoscope so theretractor is next to the target tissue.

In some embodiments disclosed herein, the endoscopic working instruments(tools) for treating the target tissue are inserted directly through arespective lumen or channel of the multi-lumen catheter. In theseembodiments where the instruments (tools) are inserted directly into thelumen or channel of the catheter, the working instruments can have adouble curve at a distal end which can automatically assume the doublecurved position when exposed from the catheter so it curves away andthen toward the target tissue, or alternatively, the working instrumentscan have a mechanism actively controlled by the user to articulate/anglethe distal tip to obtain the first and/or second curve. In either case,the working instruments would have the double curved configuration tomaximize space as described below. In other embodiments, instead of theendoscopic working instruments (tools) being inserted directly into thechannel or lumen of the catheter, a flexible tube (instrument guide) isinserted through the lumen or channel of the catheter and acts as aguide for the instrument. That is, the flexible tube is first insertedinto the lumen or channel of the catheter and then the endoscopicinstrument is inserted through the respective flexible tube. Theflexible tube has a double curve at a distal end which can automaticallyassume the double curved position when exposed from the catheter so itcan curve away then toward the target tissue, or alternatively, theflexible tube can have a mechanism actively controlled by the user toarticulate/angle the distal tip to obtain the first and/or second curve.In these embodiments utilizing the flexible tubes, the curving andmaneuverability of the flexible tubes controls the positioning andorientation of the endoscopic instruments, and therefore the endoscopicinstruments need not be provided with a pre-curved tip or articulatingmechanisms.

The double curve wherein the distal end of the tubes curves downwardlyaway (as viewed in the orientation of FIG. 5) from the longitudinal axisof the tube and then upwardly toward and in some embodiments past thelongitudinal axis increases the distance from the opening in the tube tothe target lesion as compared to a flexible tube with a single curvecurving from the longitudinal axis toward the target lesion. Thisenhances access and maneuverability of the working tools insertedthrough the tubes. The same advantages are obtained with working toolswith a double curve as compared to a tool with a single curve.

The methods, devices, and systems taught herein can be used forminimally-invasive procedures which involves minimal access trauma andminimal collateral tissue damage during a surgical operation.Minimally-invasive surgery is desirable to reduce trauma to the patient,speed the healing process, reduce risk and, thus, reduce the length andexpense of a hospital stay by minimizing or avoiding tissue damage, orrisk of tissue damage.

The systems disclosed herein also enable triangulation to be achieved.Tissue triangulation, wherein the tissue is triangulated between twoendoscopic instruments, enhances access and maneuverability.

FIGS. 1-7 illustrate one embodiment of a system for operatively treatinggastrointestinal disorders endoscopically in and in a minimally-invasivemanner. The system has a flexible outer tube 105 configured for guidingone or more channels 110 and an endoscope 115 within the system 100. Theflexible outer tube 105 has a lumen, a proximal end (not shown), and adistal end 108 to house, for example, the channel(s) and the endoscopeduring use of the system 100. The lumen can extend from the proximal tothe distal end so the tool channels 110 can be manipulated at a proximalend by the user. The outer tube 105 can alternatively be a multi-luminaltube, so a separate lumen accommodates the endoscope and the individualtool channels, and during the use of the system 100, the channel 110 canserve as a guide through which a tool 120,125 can be inserted andmanipulated in a treatment of a target tissue 190 in thegastrointestinal tract (or other areas) of the subject. The channel 110can, for example, be in operable contact with an independentlymanipulable-and-articulable tool, and the channel can have an elevatorcomponent for moving a bendable section. Thus, the length of the channelin some embodiments is sufficient so it can extend out the proximal endof the outer tube 105 for manipulation by the user. The tool channels110 are bendable or articulable at a distal end so they angle away fromthe longitudinal axis and then toward the target tissue 190. Suchbendability can be achieved by providing tool channels (guides) 110 ofshape memory material with a shape memorized bent position as shown inFIG. 5. When contained within the lumen of the outer tube 105 forinsertion, the tool channels 110 would have a substantially straightenedposition, and when advanced from the distal end of the outer tube 105,would return to the double bent position of FIG. 5 having a first curve112 and second curve 114. The first curve extends downwardly away fromthe longitudinal axis and the second curve extends upwardly towards thelongitudinal axis. Clearly, if the system orientation changes, thedesignation “downwardly” and “upwardly” changes. The objective is tohave the distal opening in the tool channels (and/or endoscopicinstruments) face toward the target tissue, e.g., target lesion. Inother embodiments, the tool channel 110 can have a mechanism such as anelevator component or a control wire attached to a distal end which canbe pulled by the user or pulled by an actuator to move the tool channelto the double bent position. These different ways to achieve bendabilityof the tool channels can be used for the various embodiments of thesystems described herein. The advantage of this double bent position isdiscussed below.

The tool inserted through the tool channel can be any tool known to oneof skill. For example, the tool 120,125 can include a grasper, aforceps, a snare, a scissor, a knife, a dissector, a clamp, anendoscopic stapler, a tissue loop, a clip applier, a suture-deliveringinstrument, or an energy-based tissue coagulator or cutter. Thebendability of the channel 110 for moving a bendable section, often adistal end of the channel 110, manipulates, i.e., bends, the tool120,125 positioned therein. In some embodiments, at least one channel110 and/or the endoscope 115 can have at least substantial freedom tomove within the outer tube 105 during operation, or “float,” such thatthe system 100 can be considered to be a floating, multi-lumen-catheterretractor system. It should be appreciated that the terms “tool” and“instrument” can be used interchangeably in some embodiments taughtherein. As can be appreciated, the tool 120,125 can be flexible, atleast at a distal end such that when the tool channel 110 bends in amanner described herein, it also bends the tool which is positionedtherein. Alternatively, it is also contemplated that the tool 120,125can be articulable or controllably bendable or composed of shape memoryor other material so it bends without reliance on the bendability of thetool channels 110.

Although two tool channels 110 are illustrated, it should also beappreciated that a system with more than two tool channels or with onlyone tool channel can also be utilized. Additionally, the endoscope canhave a working channel for insertion of a working instrument such as agrasper or dissector.

It is also contemplated that the tools can be provided with bendabilitycharacteristics so that they can be inserted directly through the lumenof the outer tube 105 without the need for tool channels. In theseembodiments, the tools themselves have the bendable or articulablefeature so as not to rely on the tool channels for achieving the doublecurve and bending/angling toward the target tissue.

The system includes a reversibly-expandable retractor 150, as shown inFIG. 1, that expands to form a treatment space or working chamber 160 inthe subject. The retractor 150 can be configured, for example, for theexpansion to occur distal to the distal end 108 of the outer tube 105.The retractor 150 can include retractor elements 151,152,153,154, alongwith a proximal coupler 198 operably connected to the retractor elements151,152,153,154, whether at least substantially attached and/or at leastslidably-engaged to the retractor elements 151,152,153,154, and a distalnexus or hub (or coupler) 199 for a distal point of an operableconnection with the retractor elements 151,152,153,154.

In some embodiments, the outer tube can have any dimensions believed tobe useful to one of skill for the purposes taught herein. Examples ofsuch dimensions are provided in U.S. patent application Ser. No.13/913,466, incorporated herein in its entirety by reference as notedabove.

The outer tube can be manufactured from any materials know to be usefulto one of skill for the purposes taught herein. For example, the outertube can comprise a polymer, or perhaps a polymer having embedded wirereinforcement. The wire reinforcement can be a mesh, a braid, a helicalcoil or any combination thereof. The wire reinforcement can include anymaterial believed by one of skill to be useful for the purposesset-forth herein. Such reinforcements are also described in U.S. patentapplication Ser. No. 13/913,466. One of skill will appreciate that theouter tube should be flexible, elastically bendable, but sufficientlystiff torsionally to transmit torque from the handle or proximal end ofthe system to the retractor or distal end of the system.

The working space is formed to create a sufficient working distance forthe tools for treatment, e.g., polyp dissection, to enhance maneuveringand manipulating the individual tools, enabling tissue triangulation.Working space distance is also advantageously formed to enhancevisibility of the target tissue. The double bend described hereinfurther enhances the working space.

As noted above, in some embodiments, the systems can include amulti-lumen catheter having at least 2 working channels for manipulatingtools and an endoscope, each of the two working channels having 6degrees of freedom that are independent from each other and theendoscope. The ability to independently manipulate the endoscope andtools allows, for example, one instrument to retract the tissue orlesion away or substantially perpendicular to another instrument, forexample, the dissecting instrument, while independently optimizing theendoscope's position and, hence, the view of the treatment area. Thiswould facilitate the removal of tissue with clear margins. The channelscan manipulate the tools with several degrees of freedom, 6 degrees offreedom in some embodiments, providing a greatly enhancedmaneuverability in the working area when compared to currentstate-of-the-art systems. In some embodiments, the at least oneindependently manipulable-and-articulable tool can be independentlymovable to various angles up to about 360 degrees.

FIGS. 1-8 illustrate how a system as taught herein can be positioned fortreating a lesion in the ascending colon C, according to someembodiments. The description herein regarding removal of a polyp fromthe wall of the colon is shown and described by way of example as thesystem (as well as the other systems disclosed herein) can be used forother surgical applications and in other body spaces. The system can beinserted into the colon C in the non-expanded position of FIG. 1 totreat lesion 190 (FIG. 5). A lesion can be identified by endoscope 115.A sheath or cover can be positioned over the retractor elements 151,152, 153, 154 to facilitate insertion, with the distal end of the sheathabutting the distal coupler 199 or alternatively overlying the distalcoupler. After insertion to the target site, the sheath is removed toexpose the retractor elements for subsequent expansion to the positionof FIG. 3. In some embodiments, the retractor elements can be biased toan expanded position and retained in a collapsed delivery position bythe sheath. In such embodiments, removal of the sheath to expose theretractor elements would enable the retractor elements to automaticallyexpand to their expanded position of FIG. 3.

Expansion of the retractor elements 151, 152, 153, 154 creates asubstantially symmetric working space 160 adjacent the lesion 190. Theretractor 150 in some embodiments can be expanded by moving distalcoupler 199 and proximal coupler 198 relative to one another, wherein asthe distance between the couplers 199, 198, shortens, the retractorelements are forced more laterally with respect to the longitudinal axisof the outer tube (catheter) 105. In alternate embodiments, theretractor elements can be operably connected to an actuator such thatthe actuator is moved to bow the retractor elements such as in theembodiment of FIG. 11 discussed in detail below. In still otheralternative embodiments, the retractor elements can be composed of ashape memory such as Nitinol or other material such that when exposedfrom the outer tube or from a sheath covering the outer tube, theyautomatically return to their expanded configuration, e.g., their shapememorized expanded configuration. When such shape memorized retractorelements are utilized, once exposed they would automatically move fromthe position of FIG. 1 to the position of FIG. 3.

The system 100 has (i) at least one independently manipulable scope 115,which can be articulable, to be used in viewing the lesion 190, (ii) atleast one tool channel 110 for at least one independentlymanipulable-and-articulable tool 120,125 to be used in the treating ofthe lesion 190, and (iii) the retractor 150. The retractor 150 can belocated distal to the distal end 108 of the outer tube 105. The treatingof the lesion 190 can include, for example, (i) viewing the lesion 190with the articulating scope 115 and (ii) using the at least one tool120,125 in the treatment of the lesion 190 with a multidirectional andmulti-angular approach to the lesion 190.

In some embodiments, the independently manipulable-and-articulable scope115 and the at least one tool 120,125 can be independently movableaxially in the working area 160, independently rotatable in the workingarea 160, and independently bendable in at least one direction in theworking area 160. The retractor provides a larger working area 160 forthe treating of the lesion 190 without overstretching, damaging orrupturing the colon.

Note that after the retractor system 150 is expanded as shown in FIG. 5,the endoscope 115 can be articulated in the working space 160 toward thetarget lesion 190 to improve visibility.

FIG. 5 illustrates a multidirectional and multi-angular approach to thelesion 190, showing the step of positioning the work area 160, endoscope115, and tools 120,125 in relation to the lesion 190. After theretractor 150 is expanded as shown in FIG. 5, the user of the system 100can view and approach the lesion 190 with the tools 120,125 from nearlyany desired angle within the working space 160. The tool channels 110 asdescribed above have a first bend or curve 112 extending away fromlesion 190 to increase the distance from the lesion and a second bend orcurve 114 extending toward the lesion 190 so endoscopic tools insertedthrough the tool channels 110 can be directed toward the lesion 190. Inthis manner, the distance from the tool channel opening to the lesioncan be maximized and in some embodiments (by reducing the length of thetool channel distal of the second curve such as in FIG. 18A discussedbelow) be substantially equivalent to the distance from the tool channelopening to the lesion in the asymmetric chamber of FIGS. 9, 10A and 10Bwhich illustrate the asymmetric chamber of copending commonly assignedapplication Ser. No. 13/913,466. By comparing the symmetric chamber withdouble curve tool channel 110 of FIGS. 5, 6 and 7 to the single curvetool channels 220 of the asymmetric working space 260 of FIGS. 9, 10A,10B formed by retractor elements 251, 252 it can be appreciated that therespective distance to the lesion 190 is increased and in someembodiments can be substantially the same such that access, vision andmaneuverability of the endoscopic tools is not compromised with the useof a symmetric chamber (the symmetric chamber expands less).Triangulation is also achieved as shown in FIGS. 7 and 10B.

Referring back to FIGS. 5-7, the tool channels 110 as shown are advancedthrough the respective lumens in the multi-lumen catheter or tube 105and the endoscopic tools or instruments are inserted through the toolchannels 110, with the distal ends of the tools extending distally ofthe respective tool channel 110. The advantages of the tool channels aredescribed below in more detail in conjunction with the embodiment ofFIG. 11, and such advantages are applicable to this and otherembodiments utilizing the tool channels. As noted above, it is alsocontemplated that in alternative embodiments, the endoscopic tools canbe inserted directly into the lumens of the catheter or tube, withoutthe use of tool channels, provided they have the doublebending/articulating characteristics described above which enable theirmanipulation without the use of bendable/articulatable tool channels.

As shown, the different angling of the tools 120,125 advantageouslyachieves tissue triangulation to facilitate access, maneuverability andremoval of the lesion. Note the dissection tool for excising the lesion190 from the gastrointestinal tract can in some embodiments be in theform of an electrosurgical instrument, although otherdissecting/excising tools can also be utilized. The excised lesion 190can be released into the retractor assembly in preparation forcompletion of the procedure. The tool for excision of the lesion 190 canbeen replaced by another tool for closure of the lesion. The defect canbe closed by various methods such as mechanical (e.g., clips staples orstructures), glue, electrosurgical energy, etc. After capture of thelesion 190 in the retractor 150, the retractor can be collapsed tocontain the lesion 190 within the collapsed retractor elements 151, 152,153, 154 in preparation for removal of the system from the subject,including the use of an optional retractor cover which can be slid overthe catheter to further encapsulate the lesion retained within thecollapsed retractor elements.

The distal nexus or hub 199 is shown in the shape of a ring, although itcan be virtually any shape desirable to one of skill, such as a cone,hemisphere, sphere, and the like, and it may or may not include a portfor passage of the endoscope beyond the distal end of the system. Asnoted above, in some embodiments, the proximal coupler 198 can be movedtoward the distal coupler 199, the distal coupler moved toward theproximal coupler 198, or both couplers moved toward each other to reducetheir distance to force the retractor elements radially outwardly. Theextent of outward expansion of the retractor elements can be controlledby controlling the distance between the proximal and distal couplers198, 199, The retractor 150 can be repeatedly moved between expanded andretracted positions as desired by adjusting the distance between thecoupler 198, 199. Such controlled expansion of the retractor elementscan also be achieved by operatively coupling the proximal end of theretractor elements to an actuator as in the embodiment of FIG. 11.Alternatively, as noted above, the retractor elements can be composed ofa material, e.g., shape memory material, to automatically expand whenexposed from a catheter or sheath.

In some embodiments, the retractor can be reversibly stabilized bystiffening an otherwise flexible arrangement of the retractor 150 suchas in the embodiment of FIG. 3. The stabilization of the retractor 150can, in some embodiments, include a stabilizer having, for example, anat least substantially-rigid beam 175 to support the expanded retractor150. The substantially rigid beam 175 can be substantially rectangularin cross-section, substantially circular in cross-section or of othercross-sectional shapes. It can be provided of the same or of a stiffermaterial than the retractor elements. It helps to create a morestabilized chamber as described herein. The beam 175 can be formed bythe more rigid element exposed when the retractor elements are exposedfrom the outer tube for expansion, or alternatively, can be advancedindependently from the outer tube or formed by advancement of arigidifying structure. More than one of the retractor elements can havea rigidifying structure such that one or more of the retractor elements151, 152, 153 and 154 can be stabilized.

In the embodiments of forming the rigidifying structure from a flexiblebeam, the rigid beam can be formed from a flexible beam, in someembodiments, by slidably inserting a rigid rod over a flexible tube thatcomposes the flexible beam. More specifically, in this embodiment, theflexible beam slidably receives thereover a stabilizing or rigidifyingstructure such as a rigid rod. The rigidifying (stabilizing) structurecan be independently actuated by the user by actuating a control, suchas a slidable lever, operably connected to the rigidifying structure,such that movement of the actuator distally advances the rigidifyingstructure over the flexible beam to thereby stiffen the beam.Alternatively, the flexible beam can have a lumen to slidably receivetherein a rigidifying structure such as a rigid rod. The structure ineither version can optionally be retracted from the flexible beam toreturn the system back to the original more flexible state to aidcollapsing of the retractor system. The beam can be substantiallycircular in cross-section, although other cross-sectional shapes arealso contemplated. The rigid beam limits deflection of the distal end ofthe catheter which could otherwise occur by pressure exerted on thedistal end by the body lumen wall. The at least substantially rigid beamprevents or inhibits deformation of the retractor during creation offorces on the retractor in the expansion and prevents or inhibitsbending of the catheter tip. The forces include forces from expandingtissue outwards as well as the initial forces applied on the retractorelements to create the working space. The rigid rod can be a straightcomponent comprising a rigid material, for example stainless steel oranother metal or alloy, that is slidable in and out of the innerdiameter (lumen) of the flexible tube (or alternatively over the outerdiameter of the flexible tube). The rigid rod can be pushed forward(i.e., orally) into (or alternatively over) the flexible tube to stiffenand straighten the flexible tube as in the embodiments described above.By pushing the rigid rod across the length of the flexible tube, theflexible tube, or flexible beam, becomes rigid and straight, and ineffect renders the whole retractor structure at least substantiallyrigid and straight to stabilize the retractor system. The flexible tube,or flexible beam, may also comprise a series of rigid tubes having aflexible, non-stretchable cable passing through the lumens of the tubes.When the cable is relaxed, the series of rigid tubes can be separatedusing, for example, a compressible component such as a spring betweeneach of the series of rigid tubes to provide a flexible non-overlappingconfiguration. When the cable is tensioned, the compressible componentscompress, and the rigid tubes overlap, converting the flexible beam intoa rigid beam. Such alternative mechanisms can be utilized with any ofthe embodiments described herein. Thus, during insertion of the systeminto a tortuous body lumen, for example a colon, the retractor can beunexpanded and flexible. This flexibility allows the retractor to bendto conform to the bends in the tortuous body lumen, so that it can beadvanced with ease and not cause trauma to the lumen. Once the retractoris advanced to the target location in the lumen, the flexible beam ofthe retractor can be straightened and stiffened as described herein.Since the system can be flexible and torsionally stiff, the proximalshaft or the handle can be easily rotated as desired relative to thelocation of the target lesion.

In some embodiments, the flexible beam can include a polymer. Theflexible beam can be, for example, a flexible tube that is reinforcedwith metal wires, braids, or coils that include, for example, a metalsuch as a stainless steel or NITINOL. In some embodiments, the flexibletube can be kink resistant and transmit torque. And, in someembodiments, the flexible tube can comprise a combination of bothflexible sections and rigid sections. In these embodiments, a flexiblesection can lie-between rigid sections, for example. Such flexible tubescan include composites of overlapping tubes joined using any methodknown to one of skill, including bonding using epoxy or cyanoacrylates,in some embodiments.

FIG. 3A illustrates an alternative embodiment of the retractor system250 which is identical to the retractor system 150 of FIG. 3 except arigid beam is not provided. Otherwise the components are identical tothe retractor system 150 and are labeled for convenience in the “200”series so the system 250 includes retractor elements 251, 252, 253 and254, proximal hub 298, distal hub 299 and tool channel (or instrument)lumens 206 a, 206 b.

A bridge member can be utilized to add stability to the retractor. Forexample, the retractor system 150 can include a bridge member 144configured to maintain a desired orientation of the retractor elementsduring the expansion, the bridge member 144 operably stabilizing atleast two 151,152 of the four retractor elements 151,152,153,154. Thatis, in the embodiment of FIG. 3, the bridge member 144 is attached tothe two retractor elements 151, 152. The bridge member 144 creates atransverse structure for the elements 151,152, limiting side-to sidemovement. Bridge member 144 can also include a second bridge sectionconnected to bridge 144 and to retractor elements 153 and 154 therebyconnecting all four retractor elements 151, 152, 153, 154. The bridgemember 144 can be a separate component or alternately integrally formedwith one or both of the retractor elements 151, 152. The bridge membercan be composed of a material similar to the elements 151, 152 or can becomposed of a different material.

Additional bridge members can be provided on the retractor elements toincrease stability. Note that one or more bridge members can be usedwith the other retractor embodiments disclosed herein.

In some embodiments, the bridge member 144 can be configured to reducedrag from surrounding tissue during use. For example, the bridge member144 can be configured to facilitate a movement of the system in agastrointestinal tract by designing the bridge member 144 to include aforward component 144 a that is inclined to facilitate forward movementorally, and a reverse component 144 b that is inclined to facilitatereverse movement anally.

In some embodiments, the bridge can be designed to flex to prevent theretractor elements from collapsing towards each other or bending awayfrom each other, while also providing some spring or elasticity to thesystem to comply gently with the tissue. One of skill will appreciatethat the bridge can comprise any suitable material that provides thematerial characteristics desired. For example, the bridge can be formedfrom a curved nitinol wire. The ends of the nitinol wires can beconnected to the retractor elements using any manufacturing processdeemed including, for example, tubing connectors, adhesives, or solder.

The systems taught herein can have an outer tube that iswire-reinforced, such as mesh, braided, or the like, to provide kinkresistance and torqueability to the system, as well as to furtherfacilitate a positioning of the system in the subject.

FIG. 3 shows multiple lumens 106 a, 106 b. Central lumen 106 c cancontain an endoscope such as endoscope 115 described above. Lumen 106 bcan contain a first working channel for a first endoscopic tool, andlumen 106 a can contain a second working channel for a second endoscopictool. The working channels can receive the first and second toolsdirectly therein, or alternatively, receive tool channels (tool guides)described herein for angling the endoscopic tools slidably positionedtherein.

The term “tool channel” can be used interchangeably with the term“working channel” or tool guide.” In some embodiments, a channel can bea separate component placed inside the outer tube, or it can be a spaceremaining in the lumen of the outer tube between separate componentsthat were placed in the outer tube, the separate components including,for example, an endoscope, a working channel, an instrument, a guide,and the like.

The retractor elements can have a covering, which add bulk to theretractor elements 151, 152, 153, 154 by increasing its cross-sectionaldiameter. The covering 151 a, 152 a, 153 a, 154 a (FIG. 3) extends overan intermediate portion of the respective retractor elements and can bein the form of a heat shrink tubing. The covering helps controlexpansion by providing a less flexible region.

During insertion of the system into a tortuous body lumen, for example acolon, the retractor can be unexpanded and flexible. This flexibilityallows the retractor to bend to conform to the bends in the tortuousbody lumen, so that it can be advanced with ease and not cause trauma tothe lumen. Once the retractor is advanced to the target location in thelumen, the flexible beam of the retractor, if provided, can bestraightened and stiffened as described herein. Since the system can beflexible and torsionally stiff, the proximal shaft or the handle can beeasily rotated as desired relative to the location of the target lesion.

The endoscope and tools can be maneuvered independently, for example, toaccess the lesion at a greater range of angles and improve the view ofthe lesion and ability to manipulate and dissect the lesion. Forexample, a grasper can be advanced out of the instrument channel intothe working space and flexed towards the polyp, grasp the polyp andretract the tissue to expose the base of the polyp for dissection by adissection tool through the multi-channel systems taught herein.

In an alternate embodiment, the system can be floating in the outer tubeto enhance flexibility for positioning the system in a subject. Suchfloating system is described in commonly assigned co-pending U.S.application Ser. No. 13/531,477, filed Jun. 22, 2012. During use of suchfloating system, the working (floating) channel and/or endoscope arefloating such that they are (i) at least substantially attached to thelumen of the outer tube at a first proximal location (not shown) and afirst distal location and (ii) at least substantially floating in thelumen of the outer tube between the first proximal location (not shown)and the first distal location. The separate floating components increasethe flexibility and facilitate positioning the system in the subject forthe treatment of the target tissue.

Each tool channel can be operatively connected to a handle in a manneras described below with respect to the embodiment of FIG. 11. Also, insome embodiments, an actuator is provided to control the angle of thetip by controlling the degree of proximal retraction of the pull wire,with further retraction further bending the tip and less retractionbending the tip to a lesser degree. More than one tool channel can beprovided, and the multiple tool channels can be controlled by a singleactuator, or alternatively, a separate actuator can be provided for eachtool channel. Also, various mechanisms can be utilized to lock theactuator(s) in position to maintain the bent position of the tip of thetool channels.

Other mechanisms can also be utilized to control the tool channels.Alternatively, one or more of the tool channels can have the pre doublebent (double curve) tip which is substantially straight when in theinsertion position within the confines of the multi-lumen tube(catheter) and returns to the double bent position when exposed from theconfines of the catheter.

As described herein, the channels or guides (flexible tubes) can beconfigured to control the trajectory and position of instruments such asforceps in the working space created by the retractor. In someembodiments, a channel can be removed from, or inserted through, theouter tube of the system. The channels can be virtually any sizeconsidered by one of skill to be useful in the systems described herein.For example, a channel can have an inner diameter ranging from about 1mm to about 5 mm, from about 2 mm to about 4 mm, from about 1 mm toabout 3 mm, or any range therein. The length of the channel should, ofcourse, complement the length of the system. For example, the channelcan have a length ranging from about 40″ to about 72″, from about 48″ toabout 60″, from about 42″ to about 70″, from about 44″ to about 68″, orany range therein in increments of 1″.

The channels can also comprise any material or configuration known toone of skill to be suitable for the uses described herein. For example,the channels can comprise a single polymer layer, multiple polymerlayers, a wire reinforced layer, or a combination thereof.

For flexing the distal end of the channel, there can be a side lumenwith a pull wire embedded between the inner layer and the outer layer.In some embodiments, the side lumen can be located between the innerlayer and the reinforcement layer, or the side lumen can be a part ofthe inner layer. The tool (working) channels (flexible tubes or guides)positioned inside the outer tube provide a multi-lumen catheter havingmanipulable passages for independently manipulating tools from outsidethe body into the working space inside created by expansion of theretractor.

In some embodiments, two inner tubes can be positioned adjacent to theinner surface of the outer tube to provide, effectively, three separatechannels. The two inner tubes can function as two independent toolchannels while the space between these first two channels and the outertube functions as a third channel. The third channel can besubstantially larger than the other two channels. In some embodiments,the largest diameter channel can be the channel for the endoscope.

The inner tubes can be composed of various materials, such as afluoropolymer such as TEFLON for lubricity to ease tool or endoscopepassage and movements. Other materials that may be used include, forexample, polyethylene, polypropylene, PEBAX, nylon, polyurethane,silicone, and composites thereof, each of which may also be used with alubricant coating. The tubes may also comprise a metallic wirereinforcement such as a braid, mesh or helical coil, each of which maybe embedded in the tube.

The systems provided herein can be used in several different methods oftreatment. For example, the systems can be used in a method of treatinga gastrointestinal lesion using a multidirectional and multi-angularapproach to the lesion. The method can include positioning the system ina subject's gastrointestinal tract, the positioning including placingthe retractor in proximity to a target lesion for a treatment; expandingthe retractor to create the treatment space for use of the tool;treating the lesion with the tool; collapsing the retractor; and,withdrawing the system from the subject. The lesion can include, forexample, a perforation, a tissue pathology a polyp, a tumor, a canceroustissue, a bleed, a diverticuli, an ulcer, an abnormal vessel, or anappendix.

In some embodiments, it is desirable to provide a cover or sheath thatcovers a portion of the system, including the retractor during deliveryof the retractor to a target site, during a treatment of a target tissueat the target site, during a removal of the target tissue, and/or duringa removal of the system from the subject, or a combination thereof. Oneof skill will appreciate that the retractor has elements (including thebridge members) that can catch, snag, or otherwise disturb or contacttissue during delivery, or removal, of the retractor to or from thetarget site. The sheath covers a collapsed configuration of theretractor 150 to render an at least substantially smooth and/oratraumatic surface for a delivery of the retractor 150 to a target site(not shown) for a treatment of a target tissue (not shown). Also, thetreatment of the target tissue may include, for example, a dissection oftissue that can be performed within the cover without intermingling thetarget tissue with the surrounding tissues. Moreover, the dissectedtissue may be a cancerous or other tissue that is desirable to containduring treatment or removal by encapsulating it within the cover. Thus,the sheath forms a collection means for entrapping and/or pulling outresected tissue. The terms “cover” and “sheath” can be usedinterchangeably, and one of skill can appreciate that such embodimentsare open to improvements, as taught herein.

In some embodiments, the sheath is clear and is attached at one end tothe distal hub or coupler and extends proximally past the proximalcoupler or hub and is attached to the outer surface of the catheter.Alternatively, the sheath can be attached at a proximal end to proximalcoupler. The sheath can be at least substantially closed around theretractor 150 during delivery, and can be designed to open as theretractor 150 is expanded to create the working space 160 for thetreatment. Alternatively, the expansion of the retractor elements andthe sheath can be independent.

In some embodiments, the sheath can be perforated longitudinally (notshown), designed such that the sheath opens upon expansion of theretractor through tearing of the perforation at the target site. In someembodiments, a tongue-and-groove mechanism, for example a ZIPLOCKmechanism, can be used to at least substantially close a slit at the topof the retractor which can also open upon the expansion of the retractorat the target site. In some embodiments, a larger perforation, orunclosed portion, can remain in the sheath to facilitate the tearing oropening of the sheath at the target site upon the expansion of theretractor 150. In some embodiments, the terms “slit” and “opening” canbe used interchangeably.

In some embodiments, the sheath can be reversibly opened, such that thesheath can be re-closable. For example, a drawstring, cable, or wire,can be operably positioned in communication with the opening for there-closing of the opening by pulling or pushing the drawstring, cable,or wire from outside the patient during the treatment. In someembodiments, the edges of the opening can form longitudinal pockets orchannels for pulling or pushing the drawstring, cable, or wire asdesired from outside the patient during the treatment, such as byrouting the drawstring, cable, or wire through the system and, perhaps,through the handle as with the other actuation means. In someembodiments, a drawstring is used to re-close the sheath, wherein thestrings can be tensioned at the handle to close the slit, or loosened toallow the retractor to expand. In some embodiments, the sheath has astiffening strip running transversely around the mid portion of the cageto facilitate the cage wires expanding without catching on thesurrounding sheath. The stiffening strip can be another layer of thesheath welded or glued onto the existing sheath. It can also be formedas a thickened area. Alternatively, a stiffer material can be insertedin the pocket running transversely. The stiffening material may be thesame as that of the sheath.

In use, in some embodiments, when the retractor system is moved from thecollapsed insertion position to the expanded position, the expandableretractor elements are expanded away from the sheath. The sheath canremain open at a surface facing the target tissue to be treated, e.g.,removed, from the patient's body. Alternatively, the sheath can remainclosed and be opened by an endoscopic tool to receive the removedlesion.

FIGS. 11-30 illustrate alternative embodiments of the system, designatedgenerally by reference numeral 1100. System 1100 includes a multi-lumencatheter or tubular member 1110 configured to receive one or more toolchannels or instrument guides (also referred to herein as flexibletubes). FIG. 11 shows two tool channels 1122 and 1124, it beingunderstood that in some embodiments, only one tool channel can beutilized and in other embodiments more than two tool channels can beutilized, with the catheter provided with a sufficient number of lumens.The tool channels 1122, 1124 can be packaged as a kit with the catheter1110 as shown in FIG. 11. Alternatively, the tool channels 1122, 1124can be packaged separately. In other embodiments, the tool channels arepackaged already inside the lumens of the catheter 1110. Each toolchannel 1122, 1124 has a lumen (channel) to receive an endoscopicinstrument (tool) therethrough.

Tool channel 1122 has a double curve (bend) at its distal tip 1122 adefining a first curve (bend) 1122 b extending away (downwardly asviewed in the orientation of FIGS. 11 and 18) from the longitudinal axisand then transitioning into a second curve 1122 c extending in a secondopposite direction (upwardly as viewed in the orientation of FIGS. 11and 18) toward the longitudinal axis. Tool channel 1124 similarly has adouble curve (bend) at its distal tip 1124 a defining a first curve(bend) 1124 b extending away (downwardly as viewed in the orientation ofFIGS. 11 and 18) away from the longitudinal axis and then transmittinginto a second curve 1124 c extending in a second opposite direction(upwardly as viewed in the orientation of FIGS. 11 and 18) toward thelongitudinal axis. The first curve increases the distance from thedistal opening 1122 d, 1124 d of the tool channel to the target lesionas compared to a single curve which does not have a downward bend. Thetool channels (flexible tubes or guides) 1122 and 1124 are insertedthrough the proximal end of the catheter 1110 and advanced throughrespective lumens 1112, 1114 in the catheter 1110 (see FIG. 12). Asshown in FIG. 16, which illustrates a proximal portion 1113 of catheter1110, the catheter 1110 can include ports 1115, 1117, cooperating withthe lumens 1112, 1114, respectively (FIG. 12), which can include valvesto maintain insufflation when the tool channels 1122, 1124 are insertedtherethrough and translated axially therein.

When the tool channels 1122, 1124 are inserted into the lumens 1112,1114 of catheter 1110, the pre-bent tips 1122 a, 1124 a are preferablysubstantially straightened to facilitate advancement through the lumens.When the tool channels 1122, 1124 are advanced sufficiently distally sothe distal tips 1122 a, 1124 a are exposed from the confines of thewalls of the catheter lumens 1112, 1114, the tips 1122 a, 1124 a, returnto the pre-set double curved position. This can be understood withreference to FIG. 18 which illustrates in phantom the straightenedposition of the tool channels 1122, 1124 for movement within thecatheter 1110. As in the other embodiments disclosed herein, the toolchannels 1122, 1124 can be composed of superelastic material, althoughother materials to provide the curved tip which returns from asubstantially straight insertion shape to a curved shape when exposedcan also be used, such as stainless steel. Also, as in the otherembodiments disclosed herein, shape memory properties of material suchas Nitinol can be used with a memorized curved tip shape. In alternativeembodiments as described above, the tool channels 1122, 1124 can have amechanism such as a pull wire which is actuated to bend its distal end.The tool channels 1122, 1124 in the embodiments of FIGS. 11-30 areunattached to the catheter 1110 so that the user can freely controltheir axial movement from a proximal end portion 1122 b, 1124 b, duringuse. However, it is also contemplated that in alternate embodiments thetool channels can be attached to the catheter, e.g., attached atproximal and distal ends to provide floating channels.

The tool channels 1122, 1124 can optionally include markings 1123, 1125,respectively, at a region proximal to the catheter 1110 to provide avisual indicator to the user of the depth of insertion of the toolchannels 1122, 1124 through the catheter lumens 1112, 1114. The toolchannels 1122, 1124 can have a luer fitting 1127, 1129, respectively,(FIGS. 11 and 19A) with a valve, at the proximal end which can close offbackflow of insufflation gas from the body. This maintains insufflationwhen the endoscopic tool is inserted through the tool channels 1122,1124 as described below. The tool channels in an alternate embodimentshown in FIG. 19B have a hemostatic valve 1121A, 1121B connected at aproximal end of tool channels 1122′, 1124′, respectively, to maintaininsufflation during tool insertion. As shown, valves 1121A, 1121B areproximal of luer fittings 1127′, 1129′. The tool channels 1124′, 1126′are identical to tool channels 1124, 1126 in all other respects.

In the embodiment of FIG. 18, the distal tip of the tool channels 1122,1124 extend radially beyond the longitudinal axis of the tool channel1124, 1126 so the distal opening is beyond the axis. In the alternateembodiment of FIG. 18A, the distal tip 1222 a, 1224 a does not extendradially beyond the longitudinal axis so the distal opening issubstantially aligned with the longitudinal axis of the tool channels1124, 1126. This reduced length after (distal) the second curveincreases the distance from the distal open to the lesion and in someembodiments can be substantially equivalent to the distance obtainedwith the asymmetric chamber discussed above. The tool channels of FIG.18A are otherwise identical to the tool channels of FIG. 18.Alternatively, the distal opening of the tool channels could be below(as viewed in the orientation of FIG. 18A) the longitudinal axis of thetool channels to further increase the distance from the distal openingto the target lesion.

In one embodiment, the tool channels 1122, 1124 can be composed of aflexible soft material, such as Pebax. A superelastic nitinol backbonecan in some embodiments be embedded in the wall of the Pebax material,e.g., within the curved portion. Other materials are also contemplated.

Catheter 1110 also preferably has a lumen 1116 (see e.g., FIG. 16)configured and dimensioned to receive an endoscope 1200. In someembodiments, the lumen 1116 is dimensioned to receive a conventionalendoscope, e.g., a conventional colonoscope, and the catheter 1110 isbackloaded over the endoscope. This is described in more detail below inconjunction with the method of use. In alternate embodiments, the lumen1116 can receive an articulating endoscope. Moreover, in alternateembodiments, the endoscope can be inserted into the catheter andinserted into the body lumen.

With reference to FIGS. 11 and 16, catheter 1110 includes a handlehousing 1130 at the proximal portion 1113 which contains two actuators:actuator 1132 for controlling movement of the retractor system 1150 andactuator 1134 for controlling movement of the rigidifying (stabilizing)structure, if provided. Catheter 1110 also includes tubing 1139 having aluer coupling 1137 and a control switch 1175 (see FIGS. 31A, 31B) forclosing off an internal gasket 1176. The suture 1172 for closingcovering 1170 is secured by the elastomeric gasket 1176 as the switch1174 is moved from the position of FIG. 31A to the position of FIG. 31B.More particularly, in the initial position of FIG. 31A, the ball valve1174, seated in a slot in the housing 1179, does not apply a force tothe gasket 1176. This enables the suture 1172 to freely move within thelumen of the catheter. When it is desired to lock the suture 1172 inposition, i.e., after the suture 1172 is tensioned to close the covering1170, the switch 1175 is slid forward, thereby camming the ball 1174downwardly (as viewed in the orientation of FIG. 31B) to collapse thelumen in the gasket 1176 against the suture 1172 to thereby secure thesuture 1172. This locks the suture 1172 against movement which therebymaintains the covering (bag) in the closed position encapsulating thetarget tissue as described herein. Note that the reverse movement of theswitch 1175 unlocks the suture 1172 to enable free movement of thesuture 1172. Catheter 1110 also has tubing 1136 having a one-waystopcock 1038 to provide an insufflation port. This port can be used tosupplement the insufflation gas provided by the endoscope 1200. Theinsufflation gas flows through lumen 1116 in the area around theendoscope 1200 since the cross sectional dimension of the lumen 1116exceeds the cross-sectional dimension of the endoscope 1200 to leave asufficient gap. As shown, the tubings 1139, 1136 are positioned distalof the actuators 1132, 1134,

Turning now to the retractor system 1150, which forms a body lumenreshaping or reconfiguring system, and with initial reference to FIG.12, the retractor system 1150 is positioned at the distal portion 1111of the catheter 1110 (distal of proximal hub 1140) and includes flexibleretractor elements 1152, 1154 1156 and 1158. Retractor elements 1152,1154, 1156, 1158 form the expandable elements which create the workingchamber (space) within the body lumen and form a substantially symmetriccage to improve visibility and working space. With the substantiallysymmetrical chamber formed, the double curved tool channels (oralternatively double curved instruments) accommodate for this shapedchamber so as not to sacrifice distances from the target lesion whichwould otherwise occur if the tips had a single curve.

As shown by comparing FIGS. 15 and 21A, retractor elements 1152, 1154,1156, 1158 move from a collapsed insertion position wherein theypreferably do not extend beyond the transverse dimension of the catheter1110 to an expanded position wherein they bow laterally outwardly andhave a transverse dimension extending beyond the transverse dimension ofthe catheter 1110. As shown, the retractor elements 1152, 1154, 1156,and 1158 expand to both sides of a plane passing through thelongitudinal axis of the catheter 1110, thereby creating thesubstantially symmetric cage or working space 1151.

Retractor elements 1152, 1154 have a bridge member 1155 to add stabilityto the retractor and maintain a desired orientation of the retractorelements during the expansion. The bridge member 1155 is attached to thetwo retractor elements 1152, 1154, preferably at an intermediateportion, to create a transverse structure for the elements 1152, 1154,limiting side-to side movement. As shown, bridge member 1155 has a firstarm 1155 a connected to retractor element 1152 and a second arm 1155 battached to retractor element 1154. The upper surface (as viewed in theorientation of FIG. 15) can be arcuate as shown. The bridge member 1155can be a separate component attached to the retractor elements bytubular elements 1159 a, 1159 b, which are attached to retractorelements 1152, 1154, respectively. In this version, the tubular element1159 a, 1159 b has a first opening to receive the retractor element anda second opening to receive an arm of the bridge member. Note thetubular elements 1159 a, 1159 b also bulk up the diameter of theretractor elements 1152, 1154 since in some embodiments the retractorelements 1152, 1154 are about 0.035 inches in diameter (although otherdimensions are contemplated). Other methods of attachment of the bridgemembers are also contemplated. Alternately, the bridge member 1155 canbe integrally formed with one both of the retractor elements 1152, 1154.The bridge member 1155 can be composed of a material similar to theelements 1152, 1154 or can be composed of a different material. Thebridge member 1155 can also include legs 1155 d and 1155 e which areconnected to lower retractor elements 1158, 1156, respectively, toattach the bridge member to lower elements 1158, 1156, respectively, toadd to the stability of the retractor system. These leg members arepreferably composed of soft elastomeric material such as polyurethanetubing to add more structure to the cage and facilitate expansion of thecage in a more predictable fashion.

Additional bridge members (not shown) can be provided on the retractorelements 1152, 1154 to increase stability. The bridge member 1155 can,in some embodiments, in the collapsed position, extend substantiallyaxially as in FIGS. 15 and 17A, but change to angle inwardly(downwardly) toward the longitudinal axis of the catheter 1110 in theexpanded position of the retractor elements 1152, 1154 such as in FIG.21A.

An additional bridge member 1157 (or alternatively multiple bridgemembers) extends between the two lower (as viewed in orientation of FIG.15) retractor elements 1156, 1158. These elements 1156, 1158 can helpopen up the lower section of the retractor system 1150, and help formthe cage for the working space, and the bridge member(s) 1157 can helpto stabilize these elements 1156, 1158, e.g., limit side to sidemovement. The bridge member 1157 as shown has arms 1157 a, 1157 bconnecting to elements 1156, 1158, respectively. The bridge member 1157can be a separate component attached to the retractor elements bytubular elements 1161 a, 1161 b which are attached to retractor elements1156, 1158, respectively. The tubular elements 1161 a, 1161 b can have afirst opening to receive the element 1156 or 1158 and a second openingto receive an arm of the bridge member 1157. Other ways of attaching thebridge member(s) are also contemplated. Alternatively, the bridge member1157 can be integrally formed with one or both of the retractor elements1156, 1158. The bridge member 1157 can be composed of a material similarto the elements 1156, 1158 or can be composed of a different material.

Additional bridge members (not shown) can be provided on the retractorelements 1156, 1158 to increase stability. The bridge member 1157 can,in some embodiments, in the collapsed position, be substantiallyparallel with a longitudinal axis of the catheter 1110 or extendsubstantially axially such as in FIG. 15 and change to an angularposition in the expanded position of the retractor elements.

The catheter 1110 includes a proximal coupler (cap) 1140 through whichthe retractor elements extend. Handle housing 1130 includes alongitudinally extending slot 1131 (FIG. 16) along which retractoractuator 1132 axially slides. The retractor elements 1152, 1154, 1156,and 1158 are coupled to the actuator 1132 via block 1146, shown in FIGS.20A and 20B. That is, each retractor element 1152, 1154, 1156, 1158 hasa proximal extension that extends through the respective lumen in thecatheter 1150 and is connected at its proximal end to the block 1146. Inthis manner, when the actuator 1132 is moved along axial slot 1131 fromits proximal position of FIG. 20A to its distal position of FIG. 20B,the block 1146 is moved distally, thereby forcing the retractor elements1152, 1154, 1156, 1158 laterally outwardly since the elements 1152,1154, 1156, 1158 are fixedly attached to the distal coupler 1148 attheir distal ends. In one embodiment, the elements 1152, 1154, 1156 and1158 can be fixed within slots formed in the distal coupler 1148. Notethe proximal and distal couplers 1140, 1148 can have openingsdimensioned to receive an endoscope when the catheter 1110 is backloadedover the endoscope as described below. Housing 1130 can include aplurality of teeth (not shown) for engagement by a tooth coupled to theactuator 1132, thereby forming a retaining or locking mechanism toretain the retractor elements in one of several select positions. Arelease mechanism for the retaining or locking mechanism can beprovided.

Additionally, it should be appreciated that alternative ways to expandthe retractor elements can be utilized, including for example providingrelatively movable couplers 1140, 1148 to expand the retractor elements1152, 1154, 1156, 1158 in the same manner as the couplers describedabove, e.g., couplers 198, 199. The retractor elements can alsoalternatively be made of self-expanding material, such as shape memorymaterial, which expand when exposed from the catheter or sheath.

Retractor elements 1152, 1154, 1156, and/or 1158 can optionally have asmall crimp forming a flattened position at a distal end adjacent wherethey are anchored to the distal coupler 1148. This reduces the bendingstiffness at the point so it acts like a hinge to create a morepredictable direction of expansion, e.g., to deflect upwardly (ordownwardly) and slightly outwardly. This also decreases the amount offorce required to initiate the bending. Such flattened portion can alsobe used with the retractor elements of the other embodiments disclosedherein.

The retractor system 1150 can be configured to reversibly stiffen anotherwise flexible arrangement of the retractor 1150. In this regard,retractor system 1150 can include a substantially-rigid beam to supportthe expanded retractor 1150 which helps to create a more stabilizedchamber (or cage) as described herein. With reference to FIGS. 15 and17A, a flexible tube or beam 1160 is provided in the collapsedconfiguration, whereas in FIG. 17B, the retractor system has a rigidbeam that is formed from the flexible beam 1160. More specifically, inthis embodiment, the flexible beam 1160 is in the form of a rod or tube1165 having a lumen to slidably receive a stabilizing or rigidifyingstructure such as a rigid tube or rod (beam) 1162. The rigidifying(stabilizing) structure 1162 is independently actuated by the user bymovement of actuator 1134. Actuator 1134 is slidably mounted within alongitudinally extending slot of housing 1130. In the initial positionof FIG. 17A, rigidifying structure 1162 is retracted within a lumen ofthe catheter and either not engaged, or only partially engaged, withflexible tube (or rod) 1160. Rigidifying structure 1162 is attached atis proximal end to sliding block 1164 which is operably connected toactuator 1134. To rigidify tube 1160, actuator 1134 is slid distally tothe position of FIG. 17B, thereby advancing sliding block 1164 and theattached stabilizing structure 1162 distally. Such movement advances therigidifying structure 1162 through the lumen 1165 of the flexible tube1160 to the distal end 1160 a to thereby stiffen the beam. Therigidifying structure 1162 can optionally be removed from the flexiblebeam 1060 to return the system back to the original more flexible stateto aid collapsing of the retractor system 1050 by sliding the actuator1134 in the reverse direction (proximally) within the axial slot,thereby withdrawing rigidifying structure 1162 from the advancedposition within flexible tube 1160. In one embodiment, the rigidifyingstructure 1164 is in the form of a structure having a proximal anddistal metal tubular structure joined by a flexible braid polyimidetube. However, it should be appreciated that other structures are alsocontemplated. Note the structures 1160, 1162 can be substantiallycircular in cross-section, although other cross-sectional shapes arealso contemplated. The rigid beam limits deflection of the distal end1111 of the catheter 1110 which could otherwise occur by pressureexerted on the distal end by the body lumen wall.

As shown in FIGS. 17A and 17B, the actuator can include a connector 1135having a tooth or pawl 1137 to engage a tooth on the rack 1138positioned within housing 1130 to retain the rigidifying structure 1164in one of several selected positions.

In the alternate embodiment of FIGS. 17C and 17D, instead of advancing arigidifying structure within the lumen of the flexible element, therigidifying structure is advanced over the flexible element. Morespecifically, flexible beam 1160′ is rigidified by movement of arigidifying structure, e.g., tubular member 1162′, over the flexiblebeam 1160′. That is, rigidifying member 1162′ has a lumen configured anddimensioned to receive flexible beam 1160′ as it is passed thereover inthe direction of the arrow of FIG. 17C. Note that flexible element 1152has been removed from FIGS. 17C and 17D for clarity. Actuator 1134, aswell as alternative methods, can be utilized for such movement

In the alternative embodiment of FIG. 26A, the retractor system does notinclude a rigidifying structure. In all other aspects, the retractorsystem 1350, having retractor elements 1352, 1354, 1356 and 1358, is thesame as retractor system 1150.

A covering or cover 1170 is preferably provided at a distal end of thecatheter 1110. Covering 1170 in the illustrated embodiment is mountedaround the perimeter of the proximal coupler 1140 and the distal coupler1148. In some embodiments, the cover 1170 is pleated and sealed aroundthe couplers (caps) 1140, 1148 by a heat shrink wrap. The cover 1170 ispositioned around the elements 1152, 1154, 1156, 1158 in the collapsedinsertion position, with an opening in the cover 1170 facing toward thetarget tissue, e.g., the lesion to be removed. That is, in theorientation of FIG. 15, the opening in cover 1170 faces upwardly. Thecover 1170 can be configured to have an opening in the collapsedposition, or, alternatively, it can provided with a slit which can beopened due to stretching when the retractor elements 1152, 1154, 1156,and 1158 are moved to the expanded position. When the retractor elements1152, 1154 are expanded, they move past the cover 1170 toward the targettissue. Alternatively, the edges of the cover 1170 can be attached tothe retractor elements 1152, 1154, 1156, and 1158 thereby move with theretractor elements. When the target tissue is removed by the endoscopicinstruments described herein, the removed tissue is placed within thecover 1170, and the cover 1170 is closed, e.g., by a suture or string1172 shown in FIG. 29 to encapsulate the tissue and prevent leakage andseeding during removal from the body lumen. The suture 1172 can beembedded in a wall of the cover 1170 or in pockets or channels formed inthe cover 1170, where it is permanently fixed at a distal anchor point,and pulled proximally to tension the suture 1172 and close the cover1170.

The cover 1170 by covering the retractor elements 1152, 1154, 1156, 1158can provide a smooth and atraumatic surface for the delivery of theretractor system to the target site. The cover 1170 also helps toprevent unwanted tissue, e.g. the luminal walls, from entering throughthe spaces between the beam 1160 and retractor elements during thesurgical procedure.

In a preferred embodiment, the two ends of suture 1172 extend out oftubing 1139 (FIG. 11). Their proximal ends can be covered by a length oftubing to facilitate grasping by the user. The suture 1172 extendsthrough switch 1137 and tubing 1139, through a dedicated lumen (channel)in the catheter, through the covering 1170, and is looped at the distalcap (coupler) 1148 where it is attached (anchored). During theprocedure, the suture 1172 remains untensioned. After the tissue isplaced within the cover (bag) 1170, the two proximal ends of the loopedsuture 1172 are pulled proximally to tension the suture 1172 to closethe cover 1170. The switch can then be moved to frictionally engage thesuture 1172 to secure it so it locks in the tensioned position tomaintain closure of the cover 1170.

The use of the system of FIG. 11 will now be described with reference toremoving a lesion, such as a polyp, from a colon wall, it beingunderstood, however, that the system 1100 can used for other procedureswithin the colon or the gastrointestinal tract, as well as used forother procedures in other body lumens or body spaces of a patient.

Turning first to FIGS. 12 and 13, a distal viewing endoscope 1200, inwhich the system 1100 has been backloaded over the proximal end 1201, isinserted through lumen A in the colon B in a procedure to remove thetarget polyp C from the wall of the colon B. The endoscope 1200 in thisembodiment is a distal viewing scope with a wide distal viewing area ofabout 150-170 degree range so the polyp C and surrounding area can bevisualized. After placement of the scope 1200 adjacent the target issue,i.e., slightly proximal of the target polyp C, the system 1100 isfurther advanced over the endoscope 1200. Distal coupler (cap) 1148 hasan opening 1148 a, and proximal coupler (cap) 1140 has an openingcommunicating with the lumen 1116 (FIG. 16) of the catheter 1110 toenable such backloading of the endoscope 1200 and advancement of thesystem 1100 thereover. The catheter 1110 is advanced over the endoscope1200 as shown in FIG. 14 until it reaches the target site as shown inFIG. 15, with the retractor system 1150 aligned with the polyp C. As canbe appreciated, in this insertion position of the catheter 1110, theretractor system 1150 is in the non-expanded (or collapsed) position,with retractor elements 1152, 1154, 1156, 1158 preferably not exceeding,or only slightly exceeding, the transverse dimension of the catheter1110. In this position, the retractor elements are covered by thecovering 1170. As shown, in this position, the distal end 1202 of theendoscope 1200 is preferably positioned at the end of proximal coupler1140 and does not extend into the working space 1151 to thereby leavemore room for maneuvering of the endoscopic instruments within theworking space. Other positions, however, are also contemplated, e.g., insome versions the endoscope can extend into the working space 1151. Notealso in this insertion position, actuators 1134 and 1132 are in theirretracted position as shown in FIG. 16.

Next, to rigidify the retractor system 1150, the actuator 1134 is moveddistally from the position of FIG. 17A to the position of FIG. 17B (seealso the arrow in FIG. 16) to advance rigidifying structure 1162 fromthe retracted position to an advanced position within lumen 1165 offlexible tube 1160. This stiffens/stabilizes the retractor system 1150as discussed above. Note, as discussed above, the retractor system 1150can alternatively be stiffened/stabilized by advancement of arigidifying structure over the flexible element as shown in FIGS. 17Cand 17D. Also note that if the retractor system does not include astiffening/stabilizing structure such as in the embodiment of FIG. 26A,an actuator is not provided and this step is skipped.

The retractor system 1150 is now expanded. Actuator 1132 is advanceddistally from the position of FIG. 20A to the position of FIG. 20B (seealso FIG. 19). This advances block 1146 (which is operably coupled toretractor elements 1152, 1154, 1156, and 1158 as discussed above) whichforces retractor elements 1152, 1154, 1156 and 1158 laterally outwardlyto the position of FIG. 20B, thereby creating the substantiallysymmetric working space (chamber).

Next, tool channels 1122, 1124 are inserted through the ports 1115, 1117in the proximal region of the catheter 1110 (see FIG. 19A) and advancedby the user through the catheter lumens 1112, 1114 so they extend outthe distal openings of the lumens 1112, 1114 and into the chamber 1151as shown in FIG. 21A. Note as they emerge from the lumens 1112, 114, andout of the confines of the lumen walls of the catheter 1110, theirdistal tips 1122 a, 1124 a return to their double curved (double bent)position, curving downwardly, then upwardly (as viewed in theorientation of FIG. 21A) toward the polyp C. Note in FIG. 21A, theretractor elements are first expanded, followed by insertion of the toolchannels 1122, 1124 out of the catheter lumens 1112, 1114 and into theworking space 1151. However, it is also contemplated that in analternative embodiment, the tool channels 1122, 1124 can be insertedthrough the catheter lumens 1112, 1114 and into the working space 1151prior to expansion of the retractor elements 1152, 1154. This alternatemethod is shown in FIG. 21B, with the tool channel tips 1122 a, 1122 bexposed, but the retractor system 1150 still in the non-expandedposition. Note the tool channels 1122, 1124 can be independently rotatedand/or moved axially to adjust their position with respect to the polypC. As can be appreciated, the terms upwardly and downwardly as usedherein refer to the orientation of the system in the referenced Figures.If the position of the system (and target tissue) changes, theorientation and terms would also change.

After insertion of the tool channels 1122, 1124, endoscopic instrument(tool) 1210 is inserted through the luer fitting 1129 (FIG. 19A) of thetool channel 1124 and advanced through the lumen (channel) of the toolchannel. As shown in FIG. 22, a first endoscopic instrument 1210 extendsfrom tool channel 1124 and follows the double curve of the tool channel1124. A second endoscopic instrument (tool) 1220 is inserted through theluer fitting 1127 of tool channel 1122 and advanced through the lumen ofthe tool channel 1122. As shown in FIG. 23, the second endoscopicinstrument follows the double curve of the tool channel 1122. As notedabove, the tool channels can include a valve, such as the hemostaticvalves as shown in FIG. 19B, so insufflation is not lost duringinsertion and removal of the endoscopic instruments from the toolchannels. The endoscopic instruments 1210, 1220 can be moved furtheraxially as shown in FIGS. 24 and 25 to extend further from the toolchannels 1122, 1124 to contact and treat, e.g., remove, the polyp C.This movement of the endoscopic instruments shown by comparing FIGS.23-25 shows the advantage of the tool channels 1122, 1124. As can beseen, once the tool channels 1122, 1124 are in the desired position withrespect to the polyp C, they can be considered as defining a fixedcurve, the fixed curve being the second curve 1122 c and 1124 c. Thismeans that when the endoscopic instruments 1210, 1220 are axiallyadvanced, they move closer to the target polyp C, without a change incurvature and without a change in their axial position with respect tothe polyp C, thus providing an extra degree of freedom. The endoscopicinstrument 1210, which in the illustrated embodiment is a grasper,applies tension on the polyp C while the electrosurgical dissector 1220dissects/severs the polyp C from the colon wall B. Other endoscopicinstruments for polyp removal can also be utilized. Additionally, insome embodiments, a single tool channel can be utilized and anotherendoscopic instrument, e.g., a grasper or a dissector, can be insertedthrough a working channel (lumen) of the endoscope. Such instrumentationinserted through an endoscope can also be utilized with the embodimentshaving two or more tool channels.

Also note that due to the angles of the tool channels 1122, 1124 andthus the endoscopic instruments inserted therethrough, tissuetriangulation can be achieved as depicted by the dotted lines in FIG.30. Also as discussed above, the double curve (somewhat U-shaped tip)increases the distance of the distal openings in the tool channels 1122,1124 from the target tissue as compared to a tool channel with a singlecurve. This is especially advantageous when used with a substantiallysymmetric chamber which cannot form the same space as the asymmetricchamber described in the U.S. application Ser. No. 13/913,466 notedabove as the colon or body lumen has a maximum expansion before it isoverstretched or damaged. In the asymmetric expansion, reshaping canoccur with an increased distance for the working instruments from thelesion and increased working space. With the substantially symmetricchamber, the distance for the working instruments from the lesion wouldbe reduced compared to the asymmetric chamber if not for the doublecurve provided by the present invention. Maintaining this comparableincreased distance can be appreciated by comparing FIGS. 6 and 10A asdiscussed above, and further by the shorter distal length of FIG. 18A.Stated another way, the asymmetric chamber of FIGS. 9 and 10Areconfigures the lumen to increase and optimize the working space aroundthe target tissue (as it creates more space around the tissue) andincreases the distance between the target tissue and opposite wall. Inthe symmetric chamber of the present invention, a non-working space isexpanded at the expense of the working space near the target tissue.Thus, the distance between the target tissue and longitudinal axis ofthe catheter is decreased. To compensate for this decrease, the distancefrom the target tissue to the tool guides (channels) is increased by thedouble bent tip, achieving the objective of positioning the distalopening in the tool guides as far away from the target tissue aspossible. Thus, the first bend increases the distance from the distalopening of the tool guide from the target tissue. The second benddirects the distal opening toward the target lesion.

After removal of the polyp C from the colon wall B, it is placed withinthe cover 1170 as shown in FIG. 26, ready for removal from the body.Actuator 1134 can be moved proximally to return the retractor system tothe more flexible condition if desired. Actuator 1132 is movedproximally in the direction of the arrow of FIG. 27 to return theexpanded retractor elements 1152, 1154, 1156 and 1158 to their collapsedposition of FIG. 28 for removal of the catheter 1110. The string orsuture 1172 is then tensioned to close the cover (bag) 1170 as shown inFIG. 29, forming a bag to encapsulate the polyp C. The switch 1175 canthen be moved to the position of FIG. 31B to lock the string 1172 andthereby maintain the cover 1170 in the closed position. Catheter 1110 isthen removed from the colon B with the polyp C protected (encapsulated)within the cover 1170. Note that the cover 1170 is preferablytransparent so that the drawings illustrate the retractor elements,bridge members, beam, etc. However, to facilitate understanding of thecover 1170, FIG. 29 shows the retractor elements, bridge elements, beametc. in phantom insider the bag/cover 1170.

Note the endoscopic instruments can be used for partial tissueresection, for example, submucosal or subserosal resection. Theendoscopic instruments could also be utilized for full thickness tissueresection. The instruments enable removal of the lesion with healthytissue margins, thereby providing a complete, en-block removal of thepathological lesion.

One of skill will appreciate that the handle can be any of a variety ofshapes to provide a desired or ergonomic position for operation of thesystem. By way of example, the retractor actuator can be configured as afinger-activated button on the handle that slides back and forth througha slot in the handle to expand or collapse the retractor elements. Ameans for dynamically adjusting or ratcheting the retractor position canbe provided along the handle slot to lock the position of the retractorelements in place when the retractor actuator button is not pressed. Abutton on the opposite side of the handle can be operatively connectedto the stabilizer subsystem to convert the flexible beam into a rigidbeam, or convert the rigid beam into a flexible beam. The handle canhave inner channels routed axially, for example, within the body of thehandle and in communication with ports for tools and endoscopeintroduction into the outer tube. In some embodiments, the handle can beconfigured to require that the stabilizer actuator is activated beforethe retractor actuator can be activated, serving as a “safety” mechanismin the operation of the system

Without intending to be limited to any theory or mechanism of action,the above teachings were provided to illustrate a sampling of allpossible embodiments rather than a listing of the only possibleembodiments. As such, it should be appreciated that there are severalvariations contemplated within the skill in the art that will also fallinto the scope of the claims.

1. A system for performing minimally invasive procedures in a body lumenof a patient, the system comprising: a flexible catheter having a firstlumen configured and dimensioned to receive an endoscope therethroughand a second lumen configured and dimensioned to receive a firstflexible tube therethrough; a first flexible tube movable through thesecond lumen, the first flexible tube having a first channel extendingtherethrough configured and dimensioned to receive a first endoscopictool for axial movement therein, the first channel terminating in afirst distal opening, the first flexible tube having a longitudinal axisand a tube distal portion movable to a curved position with respect tothe longitudinal axis, the distal portion including a first curveextending in a first direction with respect to the longitudinal axis anda second curve extending in a second different direction with respect tothe longitudinal axis, the first flexible tube slidable axially withinthe second lumen; and a retractor system positioned at a distal portionof the catheter, the retractor system including first and secondflexible elements movable from a non-expanded insertion position to anexpanded position forming an expanded cage to form a larger workingspace, the distal portion of the first flexible tube movable within theexpanded cage, wherein the first curve increases a distance to a targetlesion from the first distal opening of the first flexible tube.
 2. Thesystem of claim 1, further comprising a covering for the retractorsystem, the covering having an opening to receive body tissue and isclosable to encapsulate body tissue for removal.
 3. The system of claim1, wherein the first flexible tube is unattached to the catheter.
 4. Thesystem of claim 1, wherein the catheter has a third lumen configured anddimensioned to receive a second flexible tube, the second flexible tubehaving a second channel extending therethrough configured anddimensioned to receive a second endoscopic tool for axial movementtherein, the second channel terminating in a second distal opening, thesecond flexible tube having a longitudinal axis and a tube distalportion movable to a curved position with respect to the longitudinalaxis, the second flexible tube slidable axially within the third lumenand the distal portion of the second flexible tube movable within theexpanded cage, the distal portion including a first curve extending in afirst direction with respect to the longitudinal axis of the secondflexible tube and a second curve extending in a second differentdirection with respect to the longitudinal axis of the second flexibletube wherein the first curve of the second flexible tube increases adistance to a target lesion from a distal opening of the second flexibletube, the second flexible tube slidable axially within the third lumen.5. The system of claim 1, wherein the retractor system further comprisesthird and fourth flexible elements, wherein upon expansion of theretractor system to the expanded position the first, second, third andfourth elements move from their collapsed insertion position outwardlyaway from a longitudinal axis of the catheter to the expanded position.6. The system of claim 1, further comprising a stabilizer, thestabilizer movable from a first position to a second position toincrease the stability and rigidity of the cage.
 7. The system of claim1, wherein a substantially symmetric cage is formed.
 8. The system ofclaim 6, further comprising a first actuator positioned at a proximalregion of the catheter and operably coupled to the stabilizer to movethe stabilizer between a first position and a second position toincrease the stability and rigidity of the cage.
 9. The system of claim1, further comprising a second actuator positioned at a proximal regionof the catheter and operably coupled to the first and second flexibleelements to move the first and second elements between the non-expandedand expanded positions.
 10. The system of claim 1, wherein the firstflexible tube includes a valve at a proximal portion to accommodate thefirst endoscopic tool without losing insufflation.
 11. The system ofclaim 1, further comprising a proximal coupler to retain a proximalportion of the first and second elements and a distal coupler to retaina distal portion of the first and second elements, wherein the proximaland distal couplers include a lumen dimensioned to receive the endoscopetherethrough when the catheter is backloaded over the endoscope.
 12. Thesystem of claim 2, further comprising a flexible closing member attachedto the covering, wherein the flexible closing member is pulled to closethe covering and a mechanism for retaining the flexible closing memberin position to maintain the covering in a closed configuration.
 13. Thesystem of claim 1, further comprising a first transverse bridge memberjoining the first and second flexible elements to increase the rigidityof the reshaping system.
 14. The system of claim 1, wherein the distaltips of the first and second flexible tubes are substantially alignedwith the longitudinal axis when positioned within the respective secondand third lumens of the catheter and return to the curved position whenexposed from the respective second and third lumens.
 15. A system forperforming minimally invasive procedures in a body lumen of a patient,the system comprising a first flexible tube insertable and movableaxially through a lumen of a flexible catheter, the first flexible tubehaving a first channel extending therethrough configured and dimensionedto receive a first endoscopic tool for axial movement therein, the firstchannel terminating in a first distal opening, the first flexible tubehaving a longitudinal axis and a tube distal portion movable to a curvedposition with respect to the longitudinal axis, the distal portionincluding a first curve extending in a first direction with respect tothe longitudinal axis and a second curve extending in a second differentdirection with respect to the longitudinal axis.
 16. A method forperforming a minimally invasive procedure in a body lumen of a patient,the method comprising: placing a flexible catheter over a proximalregion of a flexible endoscope; inserting the flexible endoscope in thebody lumen to visualize target tissue; advancing the flexible catheterover the endoscope, the flexible catheter including a retractor system;expanding the retractor system from a non-expanded insertion position toan expanded position to expand the body lumen to create a larger workingspace; maneuvering a first flexible tube within the catheter, the firstflexible tube having a double curved tip with a first curve extending ina first direction and a second curve extending in a second differentdirection, the first flexible tube being axially movable and rotatablewithin the catheter to locate and orient the curved tip; and maneuveringa first endoscopic tool within the first flexible tube, wherein thefirst flexible tube is located at a selected position to define a fixedsecond curve and the first endoscopic tool is movable axially to adjusta distance between a distal tip of the first endoscopic tool and targettissue without changing the selected position or curvature of the fixedsecond curve.
 17. The method of claim 16, further comprising the stepsof: maneuvering a second flexible tube within the catheter, the secondflexible tube having a double curved tip with a first curve extending ina first direction and a second curve extending in a second differentdirection, the second flexible tube being axially movable and rotatablewithin the catheter to locate and orient its curved tip; and maneuveringa second endoscopic tool within the second flexible tube, wherein thesecond flexible tube is located at a selected position to define a fixedsecond curve and the second endoscopic tool is movable axially to adjusta distance between a distal tip of the second endoscopic tool and thetarget tissue without changing the selected position or curvature of thefixed second curve.
 18. The method of claim 17, wherein the distalcurved tip of the first and second flexible tubes are normally curvedand are in a substantially straightened position when in a lumen of thecatheter during insertion and automatically assume a curved positionwhen exposed from the catheter.
 19. The method of claim 17, wherein thefirst and second endoscopic tools are angled toward the target tissue toachieve triangulation with the target tissue.
 20. The method of claim17, wherein the first and second flexible tubes are independentlyaxially movable and independently rotatable and are removably insertablethrough the catheter and remain unattached to the catheter.